Spray nozzles



SPRAY NOZZLES Frank Venus, Jr., Oxford, Conn., assignor to The RisdonManufacturing Company, Naugatuck, Conn, a corporation of ConnecticutApplication March 27, 1956, Serial No. 574,263

8 Claims. (Cl. 299-114) This invention pertains to spray nozzles forliquid dispensing devices, and more particularly to nozzles adapted togive good atomization of liquids which ar substantially nonvolatile atordinary ambient temperatures and which are propelled from such devicesby means of pressure.

The atomization may be efiected by supplying under pressure to a nozzlethe liquid to be dispensed, which may be done by means of a manuallyoperated pump, or preferably by means of gas pressure generated Within avalved container in which such liquid is ordinarily held. in the lattercase, the gas pressure is commonly produced by including in thecontainer a low-boiling liquid which volatilizes at ordinary roomtemperature and acts as a propellant for the first liquid when the valveof the container is actuated.

While the nozzles of the invention find general applicability indispensing any of various kinds of liquids, they are especially suitedfor use in dispenser devices of the last mentioned type wherein theliquid to be dispensed is essentially nonvolatile at ordinary ambienttemperatures, is substantially immiscible in the propellent liquid anddoes not readily form an emulsion therewith. In such instances, there ispresent in the dispensing container a three-phase system consisting oftwo liquid phases and a gaseous phase. When a dispensing device of thischar actor is used, the intake end of the conduit employed to deliverliquid to the nozzle is so positioned in the container that ordinarilyonly the non-volatile liquid is delivered to the nozzle. Unlike theso-called aerosol spray dispensing devices commonly used today for pants, insecticides and many other products in which the material to bedispensed forms a solution or emulsion with the propellant, i. e. inwhich there is a two-phase system in the container, the dispensing of aliquid in the form or a spray from a three-phase system as justdescribed cannot rely on the volatilization of the propellent liquid asthe container valve is actuated to assist in the dispersion of theliquid which it is the primary purpose to dispense. Good dispersion inthe form of a fine mist of such liquid is accordingly dependent on thepressure applied to force the liquid from the container and mechanicalmeans in the nozzle itself for breaking up the liquid into finedroplets. These two factors introduce troublesome problems to beconsidered in the production of dispensing devices which are economicalto manufacture and yet really efiective in operation.

Good atomization or fine dispersion of fluids at very low pressures ishighly desirable in many practical appli cations, for example in thecase of cosmetics and medicaments where great projection of the sprayparticles is neither necessary nor desirable. The use of low fluidpressures moreover makes possible the employment of inexpensivecontainers, as elaborate precautions against the dangers or" explosiondue to high internal fluid pressures are thus largely obviated. Owing tothe fact that spray nozzles of the type here contemplated are designedfor use more particularly with expendable containers tates Patent O2,767,023 Fatented Oct. 16, 1956 which are simply thrown away whenemptied, cost of construction is of utmost importance. Still it isessential of course that the nozzle means provide efiective atomizationat the lowest possible pressure.

The nozzles of prior spray devices are generally characterized either byrather complicated constructions heretofore found necessary to get goodresults, or else they are subiect to poor atomizing operation at the lowpressures desired to be employed. It is accordingly a principal objectof the present invention to provide a nozzle of extreme mechanicalsimplicity which nevertheless af fords excellent atomization of a liquidat low pressures.

It is a further object of the invention to provide an atomizing nozzleconsisting of a minimum number of parts of inexpensive constructionwhich can be completely assembled by automatic machinery. In the spraynozzle here disclosed only two pieces are involved, and the assembly ofthese, aside from being adapted for accomplishment by automaticmachines, does not rely upon separate securing means, such as adhesives,to retain them in assembled condition.

Nozzles embodying the inventive concept are illustrated in theaccompanying drawings and are described hereinafter. In the drawings,

Fig. 1 is a partial view in vertical section of a spray nozzle and valveassembly secured to the mouth of a glass walled container adapted tohold a fluid under pressure and to dispense such fluid through the spraynozzle on actuation of the valve assembly;

Fig. 2 is a fragmentary view on an enlarged scale of the spray nozzleshown in Fig. 1;

Fig. 3 is a plan view taken along line 33 of Fig. 2; and

Fig. 4 is a front elevational view of the spray nozzle of Fig. l.

The dispensing valve and spray nozzle assembly indicated generally at 10in Fig. 1 is secured in the mouth of a container 12 adapted to hold theliquid to be dispensed. As is conventional in dispensing devices of thetype here illustrated, this liquid is stored in the container 12 underpressure of a propellent fluid, such as one of the Freons, which isvolatile at ordinary room temperatures and pressures. The propellant isused to force the liquid to be dispensed up through an eductor tube 14leading up from adjacent the bottom of the container to the valve andnozzle assembly 10 and out through the latter in response to manualactuation of the valve to open it and allow dispensing of the fluid totake place.

For cosmetic materials it is highly desirable that glass containers beutilized, as unusual decorative effects can be most economicallyobtained to enhance the sales appeal of the item. In using such acontainer, however, unless special precautions are used to render theglass shatterproof, it is imperative for reasons of safety that very lowpressures be employed in propelling the contents in order to avoid anyliability of explosion due to defects in the container or accidentaldropping of it. Then too, it is usually not necessary or desirable thatthe fluid contents be expelled from the container with great force orprojected any great distance, but rather that a fine, uniform dispersionbe obtained which may be directed upon a given area by placing thedispenser fairly close to the object upon which the spray is to bedeposited. Accordingly if low pressures are to be used in propelling novolatile liquid contents, especially if they are substantiallyimmiscible in the propellant, the mechanical means for effecting thedispersion into a fine mist becomes all the more significant as it isnot possible to rely upon a high 7 tainer is simply one of manydifferent types which can be ticular construction of this valve isdisclosed in my pending application Serial No. 438,543, and reference tothat disclosure is made for. fuller discussion of the various details of:its construction. For purposes of the present disclosure it issuficient to state that an annular groove 16 in the periphery of ahollow valve stem- 18 which is closed at its inner end is normallysealed by encirclement of the lower end of the stem 18 by a resilientelastic gasket 20'confined within a flanged valve cup 22 by' a metal capportion 24. Communicating passages 26 are provided in the valve stembetween groove 16 and the bore 28 of the stem. In normal condition,fluid under pressure delivered to the valve cup 22 through eductor tube14 is prevented by gasket 20 from escaping from the container 12. Whendispensing is desired, the valve stem 18 is pushed laterally at itsupper endgwhereby it pivots about a point determined by abutment of aflange 27 on the valve stem against the underside of cap 24, and thiscauses the lower 1 end of the valve stem to be tilted, compressing thegrommet 20 against the side of valve cup 22. This causes a portion ofthe annular groove 16 to be exposed at the side opposite from that atwhich the stem is pushed, and fluid in the valve cup 22 is accordinglyallowed to enter into the groove 16 and bore 28 which, as seen in Fig.l,

. is open at its upper end.

An actuator head 30 is secured on the open, upper end is formed toprovide a recess or socket 40 opening onto a' substantially fiat face 42of the body 32. At the mouth 'or outer edge of this socket, the sidewalls 44 taper inwardly a short distance to provide a frusto-conicalopening. At a point approximately midway of its depth, the side wall ofthe socket 40 is undercut to provide a lip 46 which overhangs a straightwall portion 48; The bottom of socket 40, as seen best in Fig- 3, isalso formed to provide an annular groove 50 and'a' central depression52, groove 50 being spaced inwardly a short distance from side wall .48to leave an annular land 54 in the bottom of the socket. Groove 59 isspaced from central depression 52 to leave a second annular land 56disposed between the. groove and-the central depression. Feed passage 38extends throughthe bottom wall of the socket 40 into communication withpassage 36 as previously described, passage 38 intersecting groove 54?and providing communication therewith. a

The bottom Wall of socket 40 likewise has formed in it a number of slotsor grooves 58 which radiate outwardly from the central depression 52 tointersect groove 50 and provide communicating channels between thegroove and the central depression. As seen more particularly in i Fig.3, these grooves radiate tangentially from the periphcry of the centraldepression.

A cup 60 is disposed in the socket 40 of the spray nozzle body 32. Inthe illustration the cup is shown as being fabricated of relatively thinsheet metal. This'cup has a bottom wall 62 and an upstanding side wall64, and is of' deformation, cup 60 can be snapped into position byinsertion into the tapered mouth of'the socketby means of a punch, andonce past the lip 46 it is firmly locked-in'seated a of valve stem 18.As here shown, thiscompri'ses a stiff but resilient body member'32formed of a suitable plastic material and having incorporated integrallywithin it a position in the bottom of'the socket by engagement of .thlip on the rim 66 of the cup. 'Ihiscauses the cup to be continuouslycompressed against the upper surfaces of lands S4 and 56. When fluidenters feed passages 36 and 38 and progresses into the annular groove50, it is thus prevented from leaking betweenthe'undersurface of the cupand the upper surface of lands 54 and 56, and is constrained to enterthe radiating grooves 53 leading to cenorifice 68 which is pierced inthe bottom of cup 69 substantially centrally of the depression 52.

Owing to the compressing effect of the overhanging lip 46 upon'cup 60,thus assuring a tight seal of its bottom surface on the upper surface oflands 54 and 56, no ad-' hesive or other securing means is necessary tohold the cup in place and prevent leakage of fluid intothe central de?pression 52, by-passing slots 58;

It has been found that by carefully proportioning the size of thedischarge orifice 68 and feed passage 38 with respect to thecross-sectional area of grooves or slots 58, excellent atomization canbe obtained at low fluid pressures; In speaking of low pressures, thisterm is used here to signify gauge pressures under 20 lbs. per squareinch and as low as even 8 to 10 lbs. per square inch. Such low pressuresare highly desirable, as explained hereinbefore, since they minimize thedanger of'damage 'or injury resulting from explosion in case a glasscontainer is employed in the dispenserdevice.

By way of illustration, critical dimensions for a particularly suitablecommercial spray nozzle for use at propellent pressures of around 12 to18 p, s. i. g., are as follows: Using an orifice diameter of 0.016 fororifice 63 in cup 60, four radial slots 58 each 0.008" Wide by 0.008"deep, in combination witha feed passage 38 which has a diameter of0.025, gives excellent results. In the i foregoing example, the annulargroove 50 is 0.019 deep .by 0.008 wide. 7

' Other dimensions proportional to these are useful, and 'it appearsthat the ratios indicated below are substantially critical in achievingoptimum results at the-low pressures mentioned. These ratios areasfollows:

Total cross-sectional area 7 of tangential slots 58 Area of terminalorifice 68 =a'pprox' Total GI'OSSrSGObiOHQl area.

of tangential slots 58 Minimum cross-sectional area of feed passage 38In fabricating the spray nozzle, a material which has been foundexcellent in practice for the body 32 is polyethylene (e. g. Polythene)which is easily molded, has good rigidity and dimensional stability, yetpossesses sufficient resiliency to allow thenozzle cup 60 to be forcedinto place without permanent deformation of the body. As an example, inthe nozzle specifically described above, a metal cup of 0.175 outsidediameter can be snapped into a socket 40 of the same inside diameter inwhich the lip 46 overhangs the wall 48 by 0.004 to 0.005". .Making=approx. 0.52 to 0.78

the inside diameter of the socket to below the lip 46 the same as theoutside diameter of the cup 6% ensures a good tight seal atthe sidesof'the socket. The same isobtained at the bottom of the socket bymaking. the height of the 7 cup wall slightly greater than the distancefrom the under- The the various passages which arise when an excess ofcement is used. Also of course, the arrangement greatly simplifies theassemblyiug operations and permits them to be done by completelyautomatic machinery.

What is claimed is:

1. The combination in a spray nozzle of a stifi but resilient plasticbody member having a socket formed in one face thereof, the side wall ofsaid socket being undercut below said body face to provide an overhang,an annular groove and a central depression formed in the bottom of saidsocket, said groove being spaced from said central depression to form anannular land in the bottom of the socket, slots radiating from saidcentral depression across said land to intersect said groove and a feedpassage formed through said head and communicating with said groove tosupply fluid thereto from a supply under pressure, a cup snapped intoposition within said socket beneath said overhang, the bottom of saidcup being continuously compressed against the land in the bottom of saidsocket by elastic deformation of said plastic head resulting fromengagement of the underside of said overhang with the rim of said cup,said cup being pierced in its bottom wall to provide an orifice openinginto said central depression.

2. The combination as defined in claim 1, wherein the side wall of saidsocket tapers inwardly substantially from said body face to the point ofundercutting.

3. The combination as defined in claim 1, wherein said slots radiatetangentially from the periphery of said central depression to saidgroove, and said orifice in said cup overlies the center of saiddepression.

4. The combination as defined in claim 3, wherein the ratio of thecombined cross-sectional area of said tangential slots to the area ofsaid cup orifice is approximately 1.28. I

5. The combination as defined in claim 4, wherein the ratio of thecombined cross-sectional area of said tangential slots to the minimumcross-sectional area of said feed passage is approximately 0.52 to 0.78.

6. The combination as defined in claim 3, wherein the ratio of thecombined cross-sectional area of said taugential slots to the minimumcross-sectional area of said feed passage is approximately 0.52 to 0.78.

7. The combination in a spray nozzle for low pressure atomization whichcomprises a spray head of resilient plastic, said head being formed toprovide a cylindrical socket opening on one of its faces, the side wallof said socket having an overhanging lip adjacent the outer edge of thesocket, an annular groove formed in the bottom wall of the socket, saidgroove being spaced inwardly from the side wall slightly to provide aperipheral shoulder in the bottom of the socket, a feed passage formedin said head to deliver fluid to be atomized from a supply underpressure through said head to said annular groove, a cylindricaldepression located concentrically of said socket in the bottom wallthereof and spaced peripherally from said groove to form an annular landsurrounding said depression, grooves radiating from said depression andextending across said land to intersect said annular groove, acylindrical cup disposed in said socket, said cup being of a size tosnugly engage the side and bottom walls thereof, being slightly greaterin height than the distance from the bottom wall of the socket to theunderside of said overhanging lip whereby the bottom of said cup iscontinuously pressed into contact with the bottom wall of the socket bythe elastic deformation of the head resulting from engagement of saidoverhanging lip with the rim of said cup, said cup having an orifice inits bottom wall opening into said cylindrical depression.

8. The combination in a spray nozzle as defined in claim 7, wherein saidgrooves extending across said annular land radiate tangentially fromsaid cylindrical depression.

References Cited in the file of this patent UNITED STATES PATENTS1,289,962 Thompson Dec. 31, 1918 1,837,339 Schlick Dec. 22, 19311,919,027 Klotzman July 18, 1933 2,362,080 Martin Nov. 7, 1944 2,605,142Gold et al. July 29, 1952 2,702,957 Cooprider et al Mar. 1, 1955

